1. Field of the Invention
The present invention relates to a tin (Sn)-based solder ball and a semiconductor package, and more particularly, to a tin-based solder ball containing silver (Ag) and copper (Cu) and a semiconductor package including the same.
2. Description of the Related Art
With the trend toward highly efficient, downscaled electronic devices, miniaturizing packages during an assembly process of the electronic devices is required. Thus, solder balls are being used instead of conventional lead frames to attain miniaturization of the packages. The solder balls may serve to bond a substrate with a package and transmit signals from chips of the package to a substrate.
To reduce environmental pollution, lead (Pb)-free solder balls have been proposed. For example, although solder balls formed of a ternary lead-free solder alloy (e.g., tin (Sn)-silver (Ag)-copper (Cu)) have been suggested, the solder balls may have low thermal cyclic characteristics and be vulnerable to oxidation and solder has a low spreading and low wettability. Thus, the suggested solder balls have poor workability and weak resistance to shocks, so the solder balls are inappropriate for portable electronic products. Accordingly, there have been attempts at improving characteristics of solder balls by further adding another element to Sn—Ag—Cu, but the characteristics of the solder balls largely vary according to the kind and content of the element.